Help!!280zx MC identification

[fomoco_44]

Hi All,

I'm fairly new to the Zed universe, just been fiddling around with a mates 260z 2+2 that we use for car club events.

I have upgraded the front calipers to Hilux 4-pots and put braided lines throughout, last on the list is a larger brake MC. I purchased this one via ebay recently, advertised as a 280zx MC. Marked on the casting is 7/8, same as the original 260 unit(pic). However, when I measure the bore opening(just before the plunger) its 24mm, which is pretty close to 15/16!!.

Am I measuring the wrong part or is the marking on the casting playing silly-buggers with me?

[C.A.R.]

Get a pair of calipers & measure down the bore - that's the only way to tell for sure.

It is possible that a previous owner had the MC bored & sleeved to 15/16"

The other way is to bolt it on & see how the pedel feels...!

 

7/8" 0.875 inch = 22.225 millimeter

15/16" 0.9375 inch = 23.8125 millimeter

1" = 25.4 millimeter

[fomoco_44]

Hi Lurch,

I used a pair of digital verniers to measure inside, just didn't want to start pulling it apart.

I was under the impression that all 280zx MC's were 15/16?...i bought another one that was labeled as being off a 280z in the states, and it was also marked 7/8 (forgot to measure that one before I sold it).

 

Before i go to the drama of re-plumbing the lines, i'm trying to figure out if its worth it for this particular MC. I priced a 1" Patrol MC(JB1419) from Repco and they want $209 for it, so thats my next option if this one fails. I saw a pic of the JB1419 somewhere, and it had the outlets on the bottom, same as standard Zed's.....which seems to be different from what other people have said?

 

[PeterAllen]

Just a reminder that there are apparently two 15/16" 280ZX master cylinders. One has the mounting holes horizontal and has a one piece reservoir, the other has vertical mounting hole as per the 240/260Zs and has a two piece reservoir. The later, as I understand it, is a straight forward swap. I've not done it myself, just what I gleaned from the web!

 

The following is from Hydrid Z:

 

MASTER CYLINDERS

 

The stock master cylinder is really unsuitable for any 4 piston caliper upgrade. It works marginally for the Toyota 4 piston calipers, but really increases the pedal throw. A 79-81 280ZX master is a nice upgrade and is suggested by Modern Motorsports and Arizona Z Car when using their brake kits discussed above. There are two masters in the ZX's. The early one has dual reservoirs and fits onto a Z booster. The later one has a single reservoir and has the reservoirs clocked 90º making it incompatible with the Z booster.

 

Here is the better ZX master (79-81):